CI: bump actions/upload-artifact to v4

Author: ting-yuan

.github/workflows/auto-merge.yml

@@ -77,7 +77,7 @@ jobs:
 
       - name: Upload test results
         if: always()
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: test-reports
           path: |

.github/workflows/main.yml

@@ -74,7 +74,7 @@ jobs:
       run: ./gradlew --stacktrace --info test
     - name: Upload test results
       if: always()
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: test-reports-${{ matrix.branch }}-${{ matrix.os }}
         path: |

.github/workflows/release.yml

@@ -44,7 +44,7 @@ jobs:
       run: ./gradlew --stacktrace --info test
     - name: Upload test results
       if: always()
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: test-reports-${{ runner.os }}
         path: |